The present invention relates to speed reducers of the type frequently used in mechanical systems. More particularly, the invention relates to speed reducers having a pressure sensing device mounted thereon.
The use of speed reducers is well known in industry for translating rotational speed and torque from an input shaft to a desired rotational speed and torque at an output shaft that is connected, for example, to an industrial machine. Speed reducers typically include gear trains interfacing the input shaft with the output shaft so that an appropriate input/output ratio is achieved. Generally, the gear train is enclosed by a housing which holds lubricant for lubricating the gear train during use. Typically, the lubricant does not entirely fill the housing, the remainder of the housing interior being filled with air.
The lubricant in the housing is maintained in the housing interior by seals. During operation of the speed reducer, however, heat may be generated which could cause air and lubricant in the housing interior to expand, thus increasing the pressure on the seals. To maintain the housing interior pressure at or near the ambient exterior pressure, speed reducers typically include breathers or bellows to release or equalize interior pressure. If such a pressure equalizing mechanism becomes contaminated so that it ceases to function effectively, pressure may undesirably build in the speed reducer, possibly causing the housing seals to fail, thus leading to speed reducer failure.